I've been using LR to prepare files for commercial printing and have discovered that using a direct file Export (from a raw original as modified in the Develop module) has slightly better quality than "printing" to a jpeg file from the Print module, even with the same resizing and with no output print sharpening or with various print sharpening settings.

I see this difference via looking at the output jpegs at 100%. It appears mostly as a lack of relative sharpness or acutance in the file created from the print module, especially in detailed landscapes. Also, when print sharpening is enabled, the Print module output seems even coarser (and not as good for my landscape photos) than the same nominal setting in a File Export.

Even with the exact same pixel dimensions in the two jpgs, I always find that the actual file size as shown via Windows Explorer is smaller for the file created by the print module as compared to that from the export. This implies there is more compression via the print module function. I suppose I could partially compensate by either increasing the sharpening in the Develop module, and/or increasing the FileResolution PPI in the print module (and perhaps re-import), however doing either is a pain, and as a matter of principle I find this difference to be more in the way of a software bug that should be fixed.

Attached is a comparison from files created with no output sharpening. The direct export is at the top and the print module version is at the bottom.

I've posted on the photoshop forum but have not received any response as of yet. I've posted here regardless, as there are many advanced users on this forum.

If I understand things correctly, option 1 is to take a raw file, process it, etc. then go to File/Export. We'll select an output size (say 2000 x 3000 pixels), a resolution (say 300 ppi), jpg format, an sRGB colour space (for example) and apply no print sharpening. We'll end up with a jpg image file of ___MB.

Option 2 is to take the same processed raw file, go to the print module, set it up as a single image, and instead of printing it to paper, we print to jpg file. We set the same image size, the same resolution, same colour space and apply no print sharpening. We'll end up with a jpg image file of ___MB but the two files will be different - as can be readily seen in the example.

Both the export module and the print module have a 'quality' setting for jpg images separate from resolution. Jeffrey Friedl did a blog post about this a while back: http://regex.info/blog/lightroom-goodies/jpeg-quality Since everything else seems identical (although the print module also has a rendering intent), I wonder if this slider treats the output differently. No answers, just a question.

Mike.

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It doesn't help the OP, but I am interested to know why you say "a resolution (say 300ppi)" when you have already fixed the resolution with "output size (say 2000 x 3000 pixels)"?

This seems to be one of the most misunderstood aspects of Lightroom's treatment of files. The "resolution" field only has any relevance if you have specified the size in inches or centimetres (whereupon it will convert that size to pixel dimensions). But specify the size in pixels and the value entered in the resolution field does not affect the file in any way.

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Well there's image size 2000x3000 and DPI which aren't the same... Perhaps the disconnect lies there?

Also does the print to file take into account the particular printer you have to be using for planning on using at the time of printing to file? That might also change things as each printer has its own profile for colors etc. and it's possible the computer is adjusting the image for that color profile?? I could be way off base year as it's not my field of expertise, and when I do it I ask for the entire file as a JPEG no adjustments except that I said it to 300 dpi, and I let the picture company that I send my files to handle any issues with making the image smaller than the original if needed for printing purposes, KISS

@wolfnowlan sRGB colour space... go to the print module... same colour space... (although the print module also has a rendering intent)

The R.I. is irrelevant because the conversion to sRGB is always Rel. Col.

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@StoneNYCAlso does the print to file take into account the particular printer you have to be using for planning on using at the time of printing to file? That might also change things as each printer has its own profile for colors etc. and it's possible the computer is adjusting the image for that color profile??

The target printer would be taken into account if the conversion were to a printer profile, but wolfnowl specified sRGB, a profile that is not device specific, thus the computer (or LR) has no way of knowing what printer will be used.

The difference in jpg file size is probably a consequence of the difference in sharpness; even with the same scale value set, a sharper (and therefore more detailed) version will be compressed less. I think this is a question for Jeff. Is it possible that even with the output sharpening box unchecked in the Export dialog, some sharpening is done that is not done in the Print module?

...Even with the exact same pixel dimensions in the two jpgs, I always find that the actual file size as shown via Windows Explorer is smaller for the file created by the print module as compared to that from the export. ..

I do not think there is any issue/bug in LR as I believe what you are seeing is normal and can be explained easily by ppi settings in the Print module.

Take a theoretical raw file with native pixel dimensions of 4288x2848 and select Export set for JPEG, Quality 100, sRGB and any ppi you like the file will remain exactly the same pixel count and file size around 8.5MB.

Now go into the Print module Print to: JPEG File and set to the same sRGB profile and now you must select your File resolution. This will affect the file size and probably explains what you are observing.

For instance saving the same image @ 150ppi yields a 3.67 MB file with a 2847x1947 pixel count, @300ppi will give an 11 MB file with a pixel count of 5695x3895, @600ppi increases to 30+ MB at 11391x7791 pixels.

The differences I believe are due to the template (page setup) when exporting which seems to affect the size as expected. Make sure Dimensions check box is on. I see little reason to ever save a JPEG out of the Print module rather than Export. Also, depending on the template, there may be a border placed onto the image, at least it did in the one test I did.

What I have seen is the difference between file size is relatively small the example @300ppi 11 MB which does include a border vs 11.2 MB excluding the border same pixel count.

Took me a while to figure out how to remove the white border as I assumed that print to JPEG should just do a straight conversion but there was no way that borders could be adjusted in the Print module by using the sliders past the seemingly fixed minimum setting. I found that I had to make sure in the Page Setup to pick a printer that allowed borderless printing and set this option then I could reduce borders to 0 in the Print module.

I still think that the problem as described relates to the ppi and the percieved loss of sharpness when viewing on the monitor at 100% plus the fact that to get a size match side by side would require different zoom ratio thereby affecting percieved sharpness. Still the proof of the pudding must be judged on the print

Thanks to those who have responded so far. Mike aka Wolfnowl seems to have hit the mark on what I’m trying to get at. Some people have raised questions and suggestions and I’ll attempt to address them here and provide more detail to show that I’m comparing apples to apples and that there really is a problem with the software or at least design limitation - I just wish these types of things would be documented by Adobe .

I don’t own a printer and I upload my files to be printed by online labs. I usually edit a camera raw file in LR and output a jpeg file that I upload to a lab. I would prefer to use the Print Module Print to File rather than File Export because (1) I sometimes I like to incorporate a border, (2) sometimes I like to overlay an ‘Identity Plate’ and (3) I can choose Relative or Perceptual color rendering in the Print Module, wherease the Export only provides one default . I’ve read in Adobe literature that it’s Perceptual but I don’t know for sure and I think I saw an older post somewhere by Jeff Schewe to the contrary but didn’t understand his post completely.

The LR Print Module Print to File only outputs a Jpeg file.

I’ve attached screen images to show what the export and print module settings are. They have no borders, no special gizmos, just the same resizing, no print sharpening, same color space, and same rendering intent (I did both from the Print Module so that no matter what export really uses it should be covered).

File A - File Export of an edited image, cropped down, and resized downwards slightly to 4800x3000 pixels, no print sharpening. JPG Quality=100. End result file on disk is 4800x3000 pixels and size is 13.4 MB (14,128,022 bytes). See screen image of export dialog box and cropped portion of file attachments. Note, I also did an export via specifying 16" long dimension and 300ppi, and the end result file had 6 less bytes but the same pixel dimensions and visually the same result. And, another example via specifying width and height as 16"x10" 300ppi, and the end result file had the same number of bytes the 1st file, 14,128,022) and the same visual result.

My conclusion is that the Print Module Print to File has different and slightly inferior processing as compared to the File Export. OTOH it would be great if I’m wrong and I’m not using the Print Module correctly and someone could tell me how to use it properly. It would also be great If someone from Abobe would chime in and and confirm one way or the other :-)

I’ve read in Adobe literature that it’s Perceptual but I don’t know for sure and I think I saw an older post somewhere by Jeff Schewe to the contrary but didn’t understand his post completely.

IF you're exporting to an RGB working space, the rendering intent is Relative Colorimetric. Pick Perceptual, you'll get RelCol as those profiles don't have a perceptual table. Same is true for Photoshop. There is a V4 sRGB ICC profile (actually a few) floating out there which do have the Perceptual table but you'd have to install it yourself and depending on what profile you found, it may have the wrong white point.

On this end, I don't visually see a difference exporting or printing to JPEG, all settings being as equal as possible. That part isn't easy! Here's what I did:

1. Built a crop in LR that is 10x16 and cropped an image. 2. Exported that to be full size, no interpolating up or down. 3. Went to Print Module, crop is still in on. I can't build a template that is 16x10 but 15.99x9.99 is accepted. Don't know why.4. Print to JPEG. Now what was important was examining the first Exported image. Photoshop shows that to be:

13.19 x 8.24 @ 300, 3957x2473 pixels. With Resample off, I set the width to 16 exactly. The short side reads 9.999 but the important item is the resolution tag falls to 247.3

5. Back in Lightroom, I set the resolution to that value (247) and Print to JPEG. No sharpening applied in either case. 6. Back in Photoshop I open the file Printed as JPEG. It shows as exactly 16x10 @ 247. 3952x2470 pixels and what's really odd, a 2 pixel stroke around the entire image (I did not set that).

Not sure too why the pixel dimensions are different and why the stoke. Odd. Visually on screen in Photoshop, 100% and more, they appear the same. Something does appear to be off here. I've got an image with 2 extra pixels LR created from Print that is itself 5x3 pixels too small from Export. Rounding errors in the above setup?

In LR File Export I usually choose one of the three default working space profiles (Adobe RGB 1998, ProPhoto, or sRGB). (If Adobe documented the specifics on this, or if it was in books I read in the past then I must have overlooked it). Now, thanks to you, I can eliminate one area of confusion and one variable from my future print workflow :-)

IF you're exporting to an RGB working space, the rendering intent is Relative Colorimetric. Pick Perceptual, you'll get RelCol as those profiles don't have a perceptual table. Same is true for Photoshop. There is a V4 sRGB ICC profile (actually a few) floating out there which do have the Perceptual table but you'd have to install it yourself and depending on what profile you found, it may have the wrong white point.

Interesting results you found, Andrew. I don't have Photoshop itself (just LR 5.3), but I did notice that in LR Print Module the print image display shows a white border on one edge (depending on the exact paper size dimensions I specify), unless I click zoom-to-fill. In any case it seems that LR does indeed do something funky in the Print Module.

Why the developers couldn't have just done the resizing like they did for export (i.e. pixel dimensions vs. includes vs ppi) is beyond me and I suppose it would be a miracle if we find out from them the exact details, let alone that they ever fix it. This is off topic a bit, but I've also run into sporadic problems (similar to what others have reported) with some resizing options for smaller sizes, lack of correct color file being embedded (very rare) with direct export, and misc but minor anomalies.

For many photos the Print Module situation doesn't matter, but for finely detailed landscapes it matters to me, so I'll just confine myself to the direct export. For those cases where I want imprinting or borders (and where the ultimate rendering of detail matters) I'll go back to using Picture Window Pro as the final step.

On this end, I don't visually see a difference exporting or printing to JPEG, all settings being as equal as possible. That part isn't easy! Here's what I did:

1. Built a crop in LR that is 10x16 and cropped an image. 2. Exported that to be full size, no interpolating up or down. 3. Went to Print Module, crop is still in on. I can't build a template that is 16x10 but 15.99x9.99 is accepted. Don't know why.4. Print to JPEG. Now what was important was examining the first Exported image. Photoshop shows that to be:

13.19 x 8.24 @ 300, 3957x2473 pixels. With Resample off, I set the width to 16 exactly. The short side reads 9.999 but the important item is the resolution tag falls to 247.3

5. Back in Lightroom, I set the resolution to that value (247) and Print to JPEG. No sharpening applied in either case. 6. Back in Photoshop I open the file Printed as JPEG. It shows as exactly 16x10 @ 247. 3952x2470 pixels and what's really odd, a 2 pixel stroke around the entire image (I did not set that).

Not sure too why the pixel dimensions are different and why the stoke. Odd. Visually on screen in Photoshop, 100% and more, they appear the same. Something does appear to be off here. I've got an image with 2 extra pixels LR created from Print that is itself 5x3 pixels too small from Export. Rounding errors in the above setup?

Dan, now you have posted detail it is a little clearer precisely what you are seeing but no clearer to me at least why you are getting this poorer result.

Just a wild stab in the dark I notice in the Export dialogue box that you have ticked resize to fit Long edge to 4800 pixels. If you have cropped as Andrew did to 10x16 first what happens if you untick fit to long edge and leave the ppi at 300? Bear in mind that this could be leading down the garden path but...

The two files I built are not scaled exactly the same so it's not possible for me to subtract them and see that the results are identical. I see a very slight difference in sharpness in one versus the other but it's not the same size. Why LR is not allowing identical results or settings in both places is a mystery, I've never tested the two this way. Probably the 2nd or 3rd time I've even used it. Based on this white pixel anomaly alone, I wouldn't go there and just use Export.

Dan: As far as the Identity Plate goes, you could use the watermark feature in the Export module - unless you want the IP to be outside the borders of the image. I think the Mogrify plugin for LR is still around on the Photographer's Toolbox. Pre-LR4 there was no integral watermarking and the Mogrify plugin was good for that but I think it did borders and things as well. If it works it would allow you to achieve what you're trying to do with the Print module, only using the Export parameters. Pretty much the only time I print to jpg is for 'constructed images', like triptychs built in the Print module

Mike.

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Mike - thanks very much for idea of using the watermark feature of Export! I just tried it on a series of test shots and it works just great; it will be a real time saver for me. I don't use borders that much anymore so I'll let that slide for awhile. BTW, that's a stunning image you have in the triptych.Dan

Dan: As far as the Identity Plate goes, you could use the watermark feature in the Export module - unless you want the IP to be outside the borders of the image. I think the Mogrify plugin for LR is still around on the Photographer's Toolbox. Pre-LR4 there was no integral watermarking and the Mogrify plugin was good for that but I think it did borders and things as well. If it works it would allow you to achieve what you're trying to do with the Print module, only using the Export parameters. Pretty much the only time I print to jpg is for 'constructed images', like triptychs built in the Print module